Free Seas of Venus by David Drake

firing tit.
    Though the twin-sixties were heavy armament in Johnnie's terms, their use on a torpedoboat was more to disconcert enemies a thousand times larger than in the realistic hope of destroying an opponent. The feed drums were loaded with every other round a tracer. The guns spat a lash of glowing fireballs—a sight to make a hostile gunner flinch, even if he was behind 20-inch armor and watching through a remote pick-up.
    The guns belched two solid, pulsing lines of gold which converged at the laser-calculated range to the target. The lining of Johnnie's helmet clamped firmly over his ears like a punch to both sides of his head. The muzzle blasts slapped his face as the guns recoiled alternately.
    Blinking with the double shock to his vision and skin, Johnnie lifted his thumb from the trigger.
    The tiger beetle charged. It climbed over the bulldozer with a swift fluidity which suggested it had scores of legs instead of six.
    The charge was blind reflex. The creature's head had vanished. The short burst of high-explosive .60-caliber bullets had blown eyes and brain to jelly in a dozen red flashes.
    All the guns mounted on the starboard rail began firing. Passengers joined in with automatic rifles and even pistols. The beetle's armor sparkled with the dusting of tiny bullets exploding harmlessly across it.
    While the others banged ineffectively at the headless creature, Johnnie switched his feed selector from X to S—solids instead of high explosive. He squeezed the trigger again and held it down. His long burst halted the charging beetle, then knocked it backward.
    Though the mechanism still fed from the same loading drums as when the guns were set to the S position, the bursting charges in the bullets did not get the jolt of electricity necessary to prime them. Instead of exploding against the first object they struck, the bullets smashed their way through to the creature's vitals, ripping the heart and the ganglia controlling the shimmering legs.
    Johnnie stopped firing. He raised the barrels of his gun and rotated them in line with the vessel's axis again.
    Lubricant and powder smoke oozed out of the mechanism, filling the gun tub with their sickening mixture.
    The tiger beetle lay on the island's margin. The right side of its thorax was staved in and leaking white fluid. Its legs twitched feebly, but smaller predators were already appearing both from land and water to feast on the unexpected bounty.
    Uncle Dan smiled at Johnnie. "Told you I'd find you some target practice," he said.
    L7521 burbled past Island 3, a mass of shops and barracks formed of concrete and stabilized earth. There were variations of style and color, but no semblance of formal art. Despite—or perhaps because of—that, the buildings made a pleasing whole and seemed in keeping with the harsh ambiance of sea and sky around them.
    The net-protected entrance to the central lagoon was between Islands 3 and 2. Railgun emplacements flanked it. On the tip of either island was an openly displayed depth-charge mortar.
    "Shouldn't they be in pits?" Johnnie said, nodding toward the mortars as winches drew open the outer pair of nets.
    "They aren't for submarines," the Blackhorse officer explained. "Subs wouldn't get this close through the outer ring of sea-bottom sensors. But some of the local life forms are about as dangerous as a hostile sub."
    The torpedoboat slid through the narrow opening, then waited at idle as men on shore made certain that nothing had entered with L7521. Only when security was satisfied did the inner nets part to allow the little vessel into the lagoon.
    Long quays reached out from the three inhabited islands. Vessels up through the size of cruisers were moored to them, three and four deep. There were scores of submarines, their smooth black backs awash almost to the conning towers. Johnnie suspected that there were more than the ninety subs which Wenceslas' data bank credited to the Blackhorse.
    The heavy ships, the